Search Publications
Constraints on the global structure of magnetic clouds: Transverse size and curvature
Liu, Y.; Wang, C.; Richardson, J. D. +3 more
We present direct evidence that magnetic clouds (MCs) have highly flattened and curved cross section resulting from their interaction with the ambient solar wind. Lower limits on the transverse size are obtained for three MCs observed by ACE and Ulysses from the latitudinal separation between the two spacecraft, ranging from 40° to 70°. The cross-…
Thermodynamic structure of collision-dominated expanding plasma: Heating of interplanetary coronal mass ejections
Liu, Y.; Richardson, J. D.; Kasper, J. C. +2 more
We investigate the thermodynamic structure of interplanetary coronal mass ejections (ICMEs) using combined surveys of the ejecta between 0.3 and 20 AU. ICMEs are shown to have a moderate expansion in the solar wind compared with theoretical predictions. The expansion seems to be governed by a polytrope with γ ∼ 1.3 in this distance range. We find …
Effect of adiabatic cooling on the fitted parallel mean free path of solar energetic particles
Zhang, M.; Qin, G.; Dwyer, J. R.
The focused transport equation without adiabatic energy loss is widely used to model solar energetic particles' (SEP) interplanetary propagation by fitting spacecraft data. We incorporate the adiabatic energy loss effect, provided by the divergence of the solar wind flows, into the focused transport equation. The equation is then solved numericall…
A statistical comparison of solar wind sources of moderate and intense geomagnetic storms at solar minimum and maximum
Liemohn, Michael W.; Thomsen, Michelle F.; Weygand, James M. +3 more
Superposed epoch analyses of 549 storms are performed to make a comparison of solar wind features of geomagnetic storm events at solar minimum (July 1974 to June 1977; July 1984 to June 1987; July 1994 to June 1997) and solar maximum (January 1979 to December 1981; January 1989 to December 1991; July 1999 to June 2002). In this study, geomagnetic …
Semiempirically derived heating function of the corona heliosphere during the Whole Sun Month
Sittler, E. C.; Guhathakurta, M.; Ofman, L.
In spite of many recent developments in observations and models of the solar corona, the exact form of the heating function of the solar wind plasma is unknown. Here we attempt to make some progress on that problem by applying a previously developed simplified magnetohydrodynamic model to a unique synthesis of remote sensing coronal observations f…
Are high-latitude forward-reverse shock pairs driven by CME overexpansion?
Zurbuchen, T. H.; Manchester, W. B.
During its passage through the high-latitude heliosphere, Ulysses observed interplanetary coronal mass ejections (ICMEs) bounded by shocks. These forward-reverse shock pairs have only been observed at high latitude in the fast solar wind. It has been suggested (e.g., Gosling et al., 1995) that these shock pairs are the result of expansion of coron…
Small-scale solitary wave pulses observed by the Ulysses magnetic field experiment
Balogh, A.; Horbury, T. S.; Rees, A.
We present here a new class of isolated structure observed in interplanetary space. Events in this class consist of short-duration increases in the magnetic field magnitude and an associated rotation in the magnetic field direction, with a duration of the order of 30 s. After surveying the entire 14-year high-resolution (1 vector sample per 1 or 2…